Respiratory mask



FIG. 1 is a perspective view of a respiratory mask according to the present invention;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof, the left side being a mirror image of the right side;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

Broken lines in FIGS. 1-7 are for purposes of illustrating features which form no part of the claimed design. 

CLAIM The ornamental design for a respiratory mask, as shown and described. 